President Bush is gathering senior administration staff at the White House Saturday to discuss the apparent breakup of the space shuttle Columbia, minutes before it was due to land in Florida.

President Bush was briefed on the apparent breakup Saturday morning, and decided to return to the White House from the presidential retreat at Camp David, where he was scheduled to spend the weekend.

Administration officials say Mr. Bush is awaiting further information from the U.S. space agency, and will meet with senior staff Saturday afternoon.

Homeland Security spokesman Gordon Johndroe says the investigation into Saturday's apparent loss of the space shuttle is just beginning, but he says there is currently no indication that it was a terrorist attack.

Flight controllers lost contact with the space shuttle at an altitude of more than 200,000 feet, well beyond the range of surface to air missiles.